Exercising undertaken by persons training for athletic events of various types or pursuing a course of treatment for the rehabilitation of an illness, injury or the like has, in recent years, come to involve the use of various apparatus or machines. Such apparatus, machines and methods have grown out of various concepts and studies regarding physiology and physiological development and function.
One type of apparatus and method which has been used with significant success is full range exercise such as is possible, for example, through the use of the apparatus of Jones, U.S. Pat. No. 3,858,873. "Full range" exercise as used with reference to such an apparatus and method, and as used in the description which follows, is a defined term. The defined term "full range exercise" refers to exercise having positive work; negative work; rotary form movement; stretching; prestretching; automatically variable, balanced, direct resistance; resistance in the position of full muscular contraction; and substantially unrestricted speed of movement. The interested reader is referred to available publications for further explication of these characteristic features of full range exercise.
The general field of such exercise and related apparatus and methods is here referred to as "exercise physiology." The field of exercise physiology is related to sports medicine, being the field of medical study which is particularly directed to athletic sports and the like. The development of the field of exercise physiology has involved, among other things, the continuing development of apparatus and methods to accomplish precise application of exercising programs to specific muscles or muscle groups. One such muscle group which has long presented a difficult problem in approaching effective full range exercise is the abdominal muscle group.